Z-Prime Poly-Cotton Zirconia Provides The Fastest Metal Removal Of Any Zirconia Based Grain In The Market. Z-Prime Provides Cool Cutting With A Built In Grinding Aid And Is Recommended For Aggressive Use And Heavy Duty Applications. Z-Prime Is Manufactured With Active Grinding Agent That Provides Cool Cutting With Light Pressure. Excellent On Carbon Based Steels And On Stainless Steels.